This relates to communications between external devices and a platform.
Conventionally, external devices communicate with a platform (such as a computer or other processor-based device) by posing interrupts, events, and notifications to the platform. These interrupts can come at any time and have no regard for what activity is currently being undertaken on the platform.
Ideally, the platform may enter idle states to reduce power consumption. When the processor is in a reduced power consumption state and an interrupt comes in from an external device, the interrupt may cause the platform to power up to handle the interrupt. As a result, in many cases, it is difficult for the platform to minimize its power consumption because it has no effective control over the timing of the interrupts that arrive from external devices.